SenTech IR-SNIF-3 Operating instructions

SenTech Corporation

5745 Progress Road

Indianapolis, Indiana 46241

888/248-1988

FAX 317/248-2014

INSTALLATION AND OPERATION MANUAL

ENVIRONMENTAL SYSTEM IR-SNIF

SINGLE ZONE MONITOR

MODEL IR-SNIF-1,2,3

ii

APPLICABILITY

Information presented in this manual can be generally applied to all IR-SNIF-

1,2,3 refrigerant monitors. Specific details of programming and operator

interface apply to software version 5327k and later versions. To determine the

version of an IR-SNIF-1,2,3, press the “*” key. This will display momentary

screens that provide contact information for SenTech Corporation, the software

version and any options enabled in the monitor. If your monitor has a version

that is older than 4093 (smaller version number such as 3017), a version specific

appendix A, Programming and Operator Interface, is available. It can be

downloaded from the SenTech Corporation website, www.sentechcorp.com, or

directly from SenTech Corporation at 888-248-1988.

iii

Contents

SAFETY PRECAUTIONS and WARNINGS................................................................ 1

Model IR-SNIF-1,2,3 Specifications .............................................................................. 2

INTRODUCTION and OVERVIEW ............................................................................. 3

Functional Description................................................................................................ 3

Sensitivity to Refrigerants........................................................................................... 6

Factory Calibration ..................................................................................................... 6

PPM vs. Leak Rate...................................................................................................... 6

INSTALLATION ........................................................................................................... 7

Unpack and Inspect Material ...................................................................................... 7

Identify Location for Monitor, Sample Points and Alarms ........................................ 7

Electrical Power Connection....................................................................................... 9

Electrical Alarm Connections ..................................................................................... 9

Other External Connections...................................................................................... 11

STARTUP and PROGRAMMING............................................................................... 14

Apply Power ............................................................................................................. 14

Initial Screens............................................................................................................ 14

Normal Operation ..................................................................................................... 15

Initial Programming .................................................................................................. 15

FINAL TESTS .............................................................................................................. 21

Monitor Sequencing.................................................................................................. 21

Integration with External Devices ............................................................................ 21

Response to Refrigerant............................................................................................ 22

End-to-End System Test ........................................................................................... 24

Documentation.......................................................................................................... 24

PREVENTIVE MAINTENANCE & REPAIR ............................................................ 26

Preventive Maintenance............................................................................................ 26

Commonly Ordered Parts ......................................................................................... 26

Monitor Repair.......................................................................................................... 26

APPENDIX A: Programming and Operator Interface.................................................. 27

Summary ................................................................................................................... 27

Start-up Screens ........................................................................................................ 27

Operational Screens .................................................................................................. 28

Menu Screens............................................................................................................ 29

APPENDIX B: SenTech Room Volume Considerations ............................................. 37

APPENDIX C: Parts List and Wire List....................................................................... 41

TROUBLESHOOTING GUIDE .................................................................................. 43

SenTech Manufacturer's Limited Warranty.................................................................. 46

1

SAFETY PRECAUTIONS and WARNINGS

The following general safety precautions and warnings must be observed during

all phases of installation, operation, service and repair of equipment. Failure to

comply with these precautions, given here and elsewhere in the manual violates

safety standards of design, manufacture, and intended use. SenTech

Corporation assumes no liability for the customer’s failure to comply with these

requirements.

Definitions of safety symbols used on equipment and in manuals.

AC Voltage Terminal: Indicates areas of equipment where AC line

voltages are used and present a potential risk of electrocution. Areas

using line voltages should not be accessed during operation.

AC-to-DC Power Supply: Indicates AC line voltages are used and

present on portions of the power supply, including the heat sinks. A

potential risk of electrocution exists. Areas using line voltages should not

be accessed during operation.

Protective Grounding Terminal: The protective ground is to prevent

electric shock in case of an electrical fault. This symbol indicates that the

terminal must be connected to earth ground before operation of the

equipment.

Caution: This sign calls attention to a procedure or practice which if not

adhered to could result in damage or destruction to a part of the product.

Other information and precautions:

Input Power: Power should be supplied through a two-pole circuit breaker

located in a reasonable proximity to the equipment. Ensure that the voltages are

correct and an appropriate ground connection is provided.

Do Not Open the Monitor with Power Applied: Line voltages exist on the

terminal board inside the monitor and on the power supply inside (including the

heat sinks). The door to the monitor and the power supply itself are marked with

AC Voltage shock hazard warning labels. Remove power prior to opening the

door.

Installation, Maintenance and Repair: These functions should only be done by

qualified personnel following the instructions outlines in this manual. This is

Installation Category III equipment.

Pollution Degree: This equipment is designed for a Pollution Degree of 1.

Cleaning: This equipment should be cleaned by wiping with a soft clean cloth.

Intended Purpose: This equipment is designed to be used as a continuous

refrigerant monitor. It should not be used for any other purpose.

2

Model IR-SNIF-1,2,3 Specifications

Size: 10” x 12.5” x 4.75” (25.4cm x 31.2cm x 12cm)

Weight: 16 lbs. (7.2 kg)

Power: 120 or 240 Volt 50/60hz (41 Watts)

(voltage must be specified at time of order)

Temperature: 32 deg F – 125 deg F (0 deg C – 50 deg C)

Humidity: 0 – 95 % non-condensing

Atmospheric

Pressure:

75-106 Kpa

Equipment rated for indoor use only

Range: 10 – 1000 ppm Standard

Tube Length: 0 – 250 ft (0 – 76 m)

Trip Point: Low Alarm 0 – 1000 ppm

Main Alarm 0 – 1000 ppm

High Alarm 0 – 1000 ppm

Leak Wait: Varies from seven (7) seconds to three (3) minutes

depending on refrigerant concentration

Alarm

Output:

Low, Main and High alarm relays, each with four (4) form

C contacts rated 5 amps maximum

Analog

Output:

0 – 10 volt proportional to 0 – 1000 ppm

4-20 mA proportional to 0-1000 ppm (optional)

Computer

Interface:

RS-485 (optional)

3

INTRODUCTION and OVERVIEW

The SenTech Environmental System IR-SNIF-1,2,3 single zone monitor provides

an early warning of developing refrigerant leaks. The unit samples ambient air

and measures the amount of halogen based refrigerant gas in the air sample.

When the proportion of refrigerant present exceeds a trip point, the system goes

into alarm mode. Should the system assess the presence of refrigerant as a

leak, using SenTech’s “LEAK WAIT” algorithm, the user is notified. By

discovering a leak shortly after it starts, the potential loss can be reduced to

ounces of refrigerant, saving money and helping protect the environment.

Functional Description

The refrigerant monitor is composed of four major functional blocks: Pneumatics,

Infrared Bench, Control Electronics and Power Supply. Refer to figure 1 for an

overall block diagram.

Figure 1 Overall Block Diagram

Pneumatics: Refer to the figure 2 for pneumatics block diagram. Tubing from

the area to be monitored and from a reference air source (either fresh, outside

air, or interior conditioned air that is free of refrigerants) is connected to the valve

manifold. The electronics alternates between energizing the Sample air and the

Auto zero air solenoids. The diaphragm pump draws air from the selected inlet

and feeds the air through an orifice restrictor, through the infrared bench and to

the exhaust port located on the lower right side of the unit. The pressure switch

4

monitors the pressure created by the flow from the pump and the restriction

created by the orifice. Should pressure fall, a flow failure is detected, and signal

is sent to the electronics.

Figure 2 Pneumatics Diagram

Infrared Bench: Refer to the figure 3 for Infrared Bench diagram. The infrared

bench has an integrated source circuit with infrared source at one end and an

integrated detector circuit with filter and detector at the other. Presence of

refrigerant in the sample air will cause a change in the output of the detector.

Figure 3 Infrared Bench

Control Electronics: Refer to the figure 4 for control electronics block diagram.

The signal from the infrared bench is analyzed by the control circuit and

converted into a digital measurement in ppm (parts per million). The ppm level is

compared to trip points set for Low, Main and High alarm levels. If the ppm level

exceeds the Low alarm threshold, the “Leak Wait” algorithm is used to determine

5

whether the monitor has experienced a transient exposure, or a leak truly exists.

If the ppm level remains above the Low alarm threshold on completion of leak

wait, the Low alarm relay is energized. If the signal continues to increase, the

main alarm relay will be energized and ultimately the high alarm relay. Once the

system enters Low, Main or High alarm, it will remain in that mode until the

problem is cleared and the system is reset.

Figure 4 Control Electronics Diagram

Power Supply: Refer to the figure 5 for Power Supply diagram. Power is

supplied to the monitor through terminals 1, 2 and 3 of the terminal board. Line

voltage is fed through the fuse on the left side of the monitor (not shown), and to

the diaphragm pump and power supply. The power supply converts AC line

voltage to dc voltage. DC Voltage is fed through the terminal board to all of the

electrical components of the monitor.

Figure 5 Power Supply Diagram

6

Sensitivity to Refrigerants

The system is sensitive in varying

amounts to all of the halogen-based

refrigerants, those containing

molecules of fluorine, chlorine or

both. As part of the initial setup, the

specific refrigerant to be monitored is

entered into the system. The control

electronics compensates for the

differing sensitivities, resulting in a

true ppm reading for the refrigerant

specified.

Factory Calibration

The IR-SNIF-1,2,3 is calibrated at

the factory prior to shipment. The

system maintains accuracy through

automatic rezeroing. Periodically,

the system switches to the fresh air

inlet, and reestablishes a reference

signal to which it compares sample

air. This process eliminates the

potential variations caused by

changes that develop in electronics

as components age. If a change in

infrared energy or detection of the

infrared energy develops, that

change will be first measured in the

reference signal, then also in the

sample. The ppm level is based on

the ratio of the sample to the

reference. This ratio eliminates the

effect of any variations, and

eliminates the need to periodically

calibrate a monitor in the field.

PPM vs. Leak Rate

The relationship between the actual

amount of product lost and the

resulting ppm level refrigerant in the

air is complex. There is no direct

relationship between the amount of

refrigerant leaking and the

concentration being measured. The

size of the room, the location of the

pick up point, the location of the leak

and airflow in the room will all affect

the actual concentration at the inlet.

However, by judicious location of the

inlets (see installation section) and

maintaining the alarm set points at a

level not too far above ambient,

leaks should be detected

substantially before they otherwise

would be noticed. See Appendix B

for a detailed discussion of room

volume considerations. This

appendix will help to provide a

correlation between pounds of

refrigerant lost over a given period to

the ppm level measured. This

correlation can be developed for a

specific application.

7

INSTALLATION

Unpack and Inspect Material

IR-SNIF-1,2,3 Package: The IR-

SNIF-1,2,3 package contains the

following material:

1. IR-SNIF-1,2,3 Single Zone

Monitor

2. Installation and Operation

Manual

3. Hose barb fittings and 10

micron tube end filters

(one hose barb and filter

for each inlet – two of

each are provided)

4. CTS/Warranty form to be

completed and returned to

Sentech

Optional Purchases: The IR-SNIF-

1,2,3 package may also contain the

following material:

1. Plastic FRPE tubing, ¼ inch

OD for sample tube

2. Combination Horn/Strobe

alarm

3. Horn alarm

4. Strobe alarm

Other Required Material: The

following material is required but not

provided by SenTech:

1. Primary power wiring

2. Wiring for connection to alarm

devices or other building

systems

3. Relay contactors for building

system loads greater than 5

amps

4. ¼ inch tubing (if not

purchased from SenTech, or if

copper tube is required by

local code

If any material is missing, or appears

to be damaged, contact Sentech

Corporation for assistance.

Identify Location for Monitor,

Sample Points and Alarms

Monitor Location: ASHRAE-15

specifies that the refrigerant monitor

is to be located in the mechanical

room. There are two interpretations

of this: the unit itself is to be

installed in the mechanical room; or

the sample point is to be located in

the mechanical room. Because the

IR-SNIF-1,2,3 is an active air draw

monitor, it can be installed nearly

anywhere in the vicinity of the area

to be monitored.

If local codes allow, the monitor can

be installed at the entrance to the

mechanical room, with the sample

tube routed into the mechanical

room and the fresh air reference

routed to an appropriate location. If

the monitor is located outside the

mechanical room, a fitting should be

installed and an exhaust tube routed

either into mechanical room, or

outdoors. If it is routed outdoors, it

must not be located near the fresh

air reference.

If local codes require the monitor to

be physically installed in the

mechanical room, it should be

installed in the best location for ease

of use and routing of sample and

fresh air tubing. If the monitor is

installed in the same room as the

8

sample pick-up-point, no exhaust

tube is required.

Caution: Liquid can affect

the performance of the

monitor. Pick-up-points

must be protected from

exposure to water and other

liquids.

Sample Location: Since the

monitor measures the concentration

of refrigerant in the air, the pick up

point should be mounted where it is

most likely to sense leaking

refrigerant. The criteria to consider

in selecting the sample pick up point

location include:

1. As close to the area of

potential leaks as possible.

On the ‘downstream’ side of

the air flow pattern in the

room.

2. Since refrigerants are

typically heavier than air, the

pick up tube should be

terminated approximately 18

inches above the floor.

3. The sample tube should be

located such that it will

require no more than 250 feet

(75 m) of tubing.

Reference Location: Since the

monitor compares a fresh air

reference to the sample, care must

be taken in choosing a location. The

fresh air reference tube should be

routed to a location that will be free

of refrigerant. This can be, but does

not necessarily have to be, located

outdoors. If the fresh air reference is

routed outdoors, the following criteria

should be used:

1. The tube end filter must be

protected from the elements.

Water, ice or insects can

partially obstruct the tube end

filter and change the

reference signal.

2. The tube end filter must be

located such that it can be

inspected as part of the

recommended quarterly

preventive maintenance.

3. The tube end filters must not

be located near exterior

HVAC equipment, or any

potential source of

refrigerant.

Exhaust Location: The exhaust

tube is required only if the monitor is

not located in the same room as the

sample pick-up-point. If an exhaust

tube is installed, it should be run to

the room being monitored, or to an

exterior location. An exhaust tube

must not be terminated near the

fresh air reference.

Alarm Location(s): A combination

horn/strobe alarm is recommended

for a mechanical room. The alarm

should be located inside the room

such that it can be seen and heard

from any area of the room.

Additionally, a strobe alarm can be

installed at each entrance to the

room to alert the user of an alarm

prior to entry to the room itself. Note

that the IR-SNIF-1,2,3 has visual

indicators of its alarm status. If the

monitor is installed at the entrance to

the room, a strobe should not also

be required.

9

Electrical Power Connection

Caution: All installation

wiring, service and

maintenance should be

performed by a qualified

electrician in accordance

with national and local

codes.

TB-1 Power Wiring: The IR-SNIF-

1,2,3 monitor is designed to operate

on only 110 or 240 vac, but not both.

It will operate on either 50 or 60 hz.

The power supply in the monitor

automatically detects the supply

voltage. The diaphragm pump is

designed to operate only on 110-120

vac or on 220-240 vac. Refer to

figure 6 for a diagram of the terminal

board.

Figure 6.

Connect primary power to TB1 as

follows:

1. Connect Earth Ground to

TB1-1

2. Connect AC Line to TB1-2

3. Connect AC Neutral or

Common to TB1-3

Caution: Verify that the

monitor is designed for the

appropriate line voltage.

Connection of the incorrect

voltage will damage the

unit.

It is strongly recommended that

power be supplied from a two-pole

circuit breaker, located in reasonable

proximity to the system. Power

MUST NOT be supplied by plugging

into a wall socket. The unit is a

continuous monitor, and as a

continuous monitor should be

provided dedicated, permanent

power. If a wall socket is used, there

is a risk that the unit will

inadvertently be unplugged, putting it

off-line.

Electrical Alarm Connections

Alarm-to-Relay Connection: The

IR-SNIF-1,2,3 monitor alarm relay

sockets have two sets of NO/NC dry

contacts. Refer to figure 7 for a

diagram of the relay socket.

Earth Ground

AC Line In

AC Neutral In

1 2 3 4 56 7 8

Analog 1 (rs485 TX)

Analog 2 (rs485 GND)

Analog GND (rs485 RX)

10

Figure 7.

The terminals are grouped as

follows:

Terminal 5 = Common

Terminal 1 = NC

Terminal 3 = NO

Terminal 6 = Common

Terminal 2 = NC

Terminal 4 = NO

Caution: Ensure that

external relay connections

do not touch relay control

terminals 7 and 8. A short

circuit from the alarm wiring

to the relay control wiring

could damage the monitor,

the alarms or both.

Alarm-to-Relay Connection: The

typical Alarm connection uses the

common terminal and normally open

(NO) terminal to switch AC line

voltage to the strobe alarm, horn

alarm or combination horn strobe.

Unless specified otherwise, SenTech

Corporation recommends the

following connections for alarms:

1. Strobe Alarm, or Strobe

portion of Combination

Horn/Strobe connected

through LOW RELAY,

terminals 6 and 4.

2. Horn Alarm, or Horn portion of

Combination Horn/Strobe

connected through MAIN

RELAY, terminals 6 and 4.

Caution: Ensure that

external relay connections

do not touch relay control

terminals 7 and 8. A short

circuit from the exhaust fan

wiring to the relay control

wiring could damage the

monitor, the alarms or both.

Fan-to-Relay Connection: The IR-

SNIF-1,2,3 monitor alarm relay can

support a load of up to 5 amps at line

voltage. The typical high-speed

exhaust fan will have a startup

current in excess of the relay rated

amp capacity. A pilot relay or

contactor will normally be required to

energize an exhaust fan. Unless

specified otherwise, SenTech

Corporation recommends the

following connections for exhaust

fans:

1. Fan, pilot relay or contactor

connected through HIGH

RELAY, terminals 6 and 4.

BMS-to-Relay Connection: The

IR-SNIF-1,2,3 monitor alarm relay

can provide alarm indications to the

typical building management system

(BMS) for Low, Main and High alarm

levels. This connection is normally

accomplished by switching a control

voltage through the normally open

4 3

2 1

8 7

6 5

Normally Open Terminals

Normally Closed Terminals

Common Terminals

11

(NO) contacts of the respective

relay. Unless specified otherwise,

SenTech Corporation recommends

the following relay connections for

building management systems:

1. BMS discrete input connected

through LOW, MAIN and/or

HIGH RELAYS, terminals 5

and 3.

Other External Connections

TB1 Outputs: The IR-SNIF-1,2,3 is

designed to provide two standard 0-

10 volt analog outputs or two

optional 4-20 mA analog outputs or

optional rs-485 interface for use with

ACC 070 SenTech COMM LINK PC

to Refrigerant Monitor Interface, or

ACC 065 SenTech Remote Control

Panel Interface. Refer to Figure 8

for a diagram of the terminal board.

Figure 8.

0–10 Volt Analog Outputs: The IR-

SNIF-1,2,3 monitor provides two 0–

10 volt analog output proportional to

0–1000 ppm. Analog 1 provides a

signal proportional to the current

ppm level. Analog 2 provides a

signal proportional to the peak ppm

level measured. For applications

where the IR-SNIF-1,2,3 is installed

inside a mechanical room, the

analog 1 signal can be used to drive

an optional remote analog display at

the entrance to the room. This

signal could be used to provide an

analog input to building management

systems for remote monitoring of the

ppm level and for trending of levels.

This signal should NOT be used as a

replacement for discrete alarm relay

connections to a BMS. Analog

output connections are as follows:

1. Use twisted pair wire for

analog 1 connection, or four

conductor twisted wire for

both analog 1 and analog 2.

Typical low voltage solid

conductor wire is suitable for

this signal. Shielded cable is

preferred, but not always

required.

2. Route twisted pair wire into

the monitor and along the wire

harness from the back-plate

to the TB1 on the back-plate.

Secure the twisted pair

periodically to the wire

harness using tie wraps.

3. Connect the appropriate wires

to TB1-6, analog 1 plus, TB1-

7, analog 2 plus, and TB1-8,

reference ground.

4–20 mA Optional Analog

Outputs: The IR-SNIF-1,2,3

monitor provides optional 4–20 mA

analog outputs in place of the

standard 0-10 volt analog outputs.

To identify whether a monitor has 4-

20 mA analog output installed,

Earth Ground

AC Line In

AC Neutral In

1 2 3 4 56 7 8

Analog 1 (rs485 TX)

Analog 2 (rs485 GND)

Analog GND (rs485 RX)

12

examine the control board installed

on the door of the monitor. Locate

the chip sockets labeled U13 and

U14. U13 and U14 are located in

the center of the board,

approximately 3.5 inches and 2

inches from the bottom of the board.

If the monitor is configured for the

standard 0-10 volt analog outputs,

the sockets will be empty. If

configured for 4-20 mA outputs, the

sockets will have 4-20 mA drive

chips installed. Connection to the 4-

20 mA outputs is the same as for 0-

10 volt outputs.

RS-485 Optional Serial Output:

The IR-SNIF-1,2,3 monitor provides

an optional RS-485 interface in place

of the analog outputs. This interface

is for use with ACC 070 SenTech

COMM LINK PC to Refrigerant

Monitor Interface, or ACC 065

SenTech Remote Control Panel

Interface.

This interface provides the ability to

display the refrigerant levels in each

area and modify setpoints via a pc

based interface. Used in conjunction

with the ACC 070 COMM LINK, the

interface allows for complete remote

monitoring of multiple refrigerant

monitors in the same facility.

This interface also provides the

ability to display the refrigerant levels

in each area and modify setpoints

via a digital remote control interface.

Used in conjunction with the ACC

065 Remote Control Panel Interface,

the RS-485 interface allows for

complete remote control and

monitoring of multiple refrigerant

monitors in the same facility.

To identify whether a monitor has rs-

485 interface installed, examine the

control board installed on the door of

the monitor. Locate the connectors

labeled P6 and P8. Connector P6 is

located on the upper left corner of

the board (as you look at the board

from inside the door). Connector P8

is located on the center of the right

side of the board. If the rs-485

interface is installed, the cable

normally connected to the P8 (right

side) will be absent, and a cable will

be connected to P6 (upper left

corner). If your monitor is configured

for analog output, and rs-485 is

required instead, contact SenTech

Corporation technical support for

assistance.

RS-485 digital connections are as

follows:

1. Use twisted wire for RS-485

connection, either twisted

triple wire, or four conductor

twisted wire. Shielded cable

is preferred, but not always

required.

2. Route twisted pair wire into

the monitor and along the wire

harness from the back-plate

to the TB1 on the back-plate.

Secure the twisted wire

periodically to the wire

harness using tie wraps.

3. Connect the transmit

conductor to TB1-6.

4. Connect the receive

conductor to TB1-8.

5. If twisted triple wire is used,

connect the remaining wire to

TB1-7, reference or shield

ground.

6. If two twisted pairs are used,

connect one conductor from

13

each pair to TB1-7, reference

ground or shield.

Custom Control Inputs/Outputs:

The IR-SNIF-1,2,3 monitor has the

capability to be programmed for

additional optional inputs or outputs.

The control circuit in the monitor is

versatile and can accommodate

additional analog or discrete

measurement and control signals.

This circuit also has the capability to

provide additional discrete control

signals. Please contact SenTech

Corporation technical support to

determine whether specific

requirements can be provided.

14

STARTUP and PROGRAMMING

Apply Power

Caution: Before applying

power, double-check all

wiring.

Once the installation has been

completed, and wiring has been

checked, close the door to the

monitor and apply power. The unit

will go through its normal startup

checks and warm-up procedure. It is

important that the door remain

closed to ensure a proper operation.

Initial Screens

If the IR-SNIF-1,2,3 has never been

programmed, it will access default

memory settings and display the

following screen:

Once the defaults have been stored,

or if the monitor has been previously

programmed, the following screen

will be displayed. Since the monitor

is factory calibrated, and factory

programmed during quality control, it

should display this screen on initial

application of power.

Following memory initialization, the

monitor will display the copyright

screen.

The monitor will next display two

Contact and Model Information

screens. (Note: these screens can

be accessed anytime during normal

operation by pressing the “*” key.)

Following display of the contact and

model information screens, the IR-

SNIF-1,2,3 will restore any alarms

that have been saved into memory.

The corresponding lights and relays

will be energized. Any external

alarms, exhaust fans or building

management system connections

will be activated. The monitor will

then display the following optics

warm-up screen.

restore from memory

RESETTING DEFAULTS

SenTech

Corporation

Phone 1-888-248-1988

www.sentechcorp.com

Model IR-SNIF-1,2,3

Version 3017

Option Code 0

www.sentechcorp.com

SenTech Corporation

IR-SNIF-1,2,3

Gas Monitor

Optics Warm up

Timer 540 12:00

Press EN

T for Menu

15

On completion of the warm-up, the

monitor will enter Auto zero mode

and begin normal operation.

If during the startup, a fault condition

is detected, follow the instructions on

the screen, and refer to the trouble-

shooting section of this manual.

Normal Operation

During normal operation, the monitor

will display one of two basic screens.

First, it will measure the fresh air

reference and display the Auto Zero

screen. Then it will measure the

sample air and display the Auto

Sample screen.

The Auto Zero measurement will

take approximately 25 seconds, and

will be performed approximately

every 3 minutes. If the monitor

senses refrigerant in the sample air,

it will lengthen the Auto Zero time to

approximately 45 seconds.

The Auto Sample measurement will

be taken for between 1 minute and 3

minutes, depending on the tube

length programmed into the monitor.

This screen will display the ppm

reading, the time of day and the

refrigerant programmed for the

sample area.

Initial Programming

Once the IR-SNIF-1,2,3 has

completed warm-up, and entered

Auto Zero, it can be programmed.

While in Auto Zero or Auto Sample

modes, press the “ENT” key to

access the main menu.

Key selections 1, 2 and 3 are used to

display current alarms, manually

initiate Auto Zero and enter the

Manual Override mode. These

functions are discussed in Appendix

A of manual.

To program the monitor, press the

“4” key to enter Setup. The monitor

will require a password to access the

setup screens. There are five setup

passwords: 111, 222, 333, 444, 999.

The first four passwords can be

changed to user-defined codes. 999

cannot be changed.

If an incorrect password is entered,

the fourth line of the screen will

change to “Access Denied” and the

monitor will return to normal

operation.

** Auto Zero**

Timer 24 12:00

Press ENT for Menu

Auto Sample AREA 1

PPM 0 12:00

R-134A

Press ENT for Menu

1)…Alarms

2)…Rezero

3)…Manual

4)…Setup ABORT

* SenTech Monitor *

ENTER PASSWORD

Followed By ENT

Code :

0

* SenTech Monitor *

ENTER PASSWORD

Followed By ENT

ACCESS DENIED

16

When the correct password has

been entered the monitor will display

the setup screen.

Press the “3” key to enter System

Setup. System setup consists of two

screens that allow the user to

change passwords, change system

flags, test the alarm circuits and set

the time and date. The user can

toggle from one screen to the other

by using the left and right arrow

keys.

Key selections 1 and 3 are used to

change passwords required to enter

setup and to test the alarm relay

integration with building wiring.

Refer to Appendix A of manual for

instructions to change passwords.

The alarm test function is described

in the Final Test section of this

manual.

Press the “2” to enter the System

Flags screens. The system flag

screen will display information for

nine settings, displayed on two

screens. Press the ENT key to

move the cursor from one line to the

next, and press the left arrow key to

move from one line to the previous.

The autozero flag can be used to

limit the frequency of autozero

cycles. It can be set between 0 and

100. If a 0 is entered, the monitor

will enter an autozero cycle after

every area is sampled (this is the

normal default configuration).

Increasing this number will allow the

monitor to skip the autozero cycle if

the raw measurement from the IR-

Bench has not changed significantly.

That is, if the raw signal varies by

less than plus or minus 10 millivolts,

and the autozero flag is set to 10, the

monitor will not perform an autozero

cycle. NOTE: This is effectively

reducing the extreme low-level

sensitivity of the monitor. If this

feature is desired, set this flag by

increasing it in small steps, 1 or 2

digits at a time, until the monitor

stops autozeroing after every zone.

The password flag can be set to

either 0 or 1. If a 1 is entered, the

monitor will require the user to enter

a password to perform any functions

of the monitor. This feature is useful

if the monitor is installed in a public

area, and controlled access to the

monitor is needed. This flag is set to

0 by default.

Press the “ENT” to move the cursor

to the horn relay flag. The horn relay

flag can be set to 0, 1, 2 or 3. This

flag changes the function of the horn

relay to control an audible alarm.

With the flag set to the 0, the horn

relay will be disabled. The monitor

can be programmed to allow the

horn relay to be de-energized while

the monitor is still in alarm. This

1)…IR Setup

2)…N/A

3)…System Setup

4)…Contact ABORT

1)…Change Code

2)…System Flags

3)…Alarm Test

ABORT

-

>

4)…Date/Time

<

-

ABORT

17

feature is useful when the user is

troubleshooting an alarm, and wants

to work in silence. Set the horn relay

flag to 1 to activate the horn relay

when the monitor is in LOW alarm.

Set the horn relay flag to 2 to

activate the horn relay when the

monitor is in MAIN alarm. Set the

horn relay flag to 3 to activate the

horn relay when the monitor is in

HIGH alarm. This flag is set to 2 by

default.

The unit number flag is used to

identify the monitor on a RS-485

network, if that option has been

purchased. This flag is set to 1 by

default.

Press the “ENT” key to move the

cursor to the next entry. When all

entries have been viewed, press the

“ENT” key again to display the

second system flag screen

The slope flag is used for

circumstances where an individual

zone might be exposed to large

levels of refrigerant. This flag will

hold the monitor in its current mode,

whether it be autosample or

autozero, if the raw measurement

has not leveled off to a constant

measurement. For instance, after an

extremely large level of refrigerant

has been measured, the monitor

might run in autozero longer than

expected if the measured level is still

falling. Set this flag to the factory

default of 50 if no large levels are

expected. Set this flag lower if large

levels are expected.

Press the “ENT” key to move the

cursor to the TWA ALARM flag. This

flag is reserved for future

implementation of TWA

measurement. This flag should be

left at the factory default of 0.

Press the “ENT” key to move the

cursor to the FULL SCALE flag. This

flag is used to adjust the full scale

measurement for the analog output.

The factory default is 1000, meaning

that the 0-10 volt analog output

corresponds to 0-1000 ppm. This

flag should be left at the factory

default unless a custom

measurement range has been

implemented in the monitor. Consult

factory technical support for further

information if needed.

Press the “ENT” key to move the

cursor to the TWA refresh flag. This

flag is used to save peak ppm

measurements if Trending is not

implemented. A TWA refresh rate of

5 minutes corresponds to a

theoretical ten-hour time weighted

average (5 minute refresh rate times

120 saved data points yields ten-

hour average). As with the TWA

ALARM flag, this feature is not yet

implemented.

Press the “ENT” key to move the

cursor to the next entry. When all

entries have been viewed, press the

SLOPE FLAG 50 -

TWA ALARM 0

FULL SCALE 1000

TWA REFRESH 5

AU

TOZERO FLAG 0 -

PASSWORD FLAG 0

HORN RELAY FLAG 0

UNIT NUMBER FLAG 1

Page is loading ...

SenTech IR-SNIF-3 Operating instructions

SenTech IR-SNIF-3 Operating instructions

Related papers

Other documents